//C06:ep_6_8.c -- prime number.
#include <stdio.h>
#include <math.h>

int main(void)
{
    int m, i, k;
    scanf("%d", &m);
    k = (int)sqrt((double)m);
    for (i = 2; i <= k; i++)
    {
        if(m % i == 0)
        {
            break;
        }
    }
    if(i > k)
    {
        printf("%d is a prime number!\n", m);
    }
    else
    {
        printf("%d is not a prime number!\n", m);
    }
}
